1. Field of Use
This disclosure is directed to an image-forming apparatus and an intermediate transfer member.
2. Background
Image-forming apparatuses in which a color or black and white image is formed by using an intermediate transfer member to electrostatically transfer toner are well known. When an image is formed on a sheet of paper in a color image-forming apparatus using such an intermediate transfer member, four color images in yellow, magenta, cyan and black respectively are generally first transferred sequentially from an image carrier such as a photoreceptor and superimposed on the intermediate transfer member (the primary transfer). This full color image is then transferred to a sheet of paper in a single step (the secondary transfer). In a black and white image-forming apparatus, a black image is transferred from the photoreceptor, superimposed on an intermediate transfer member, and then transferred to a sheet of paper.
An intermediate transfer member is required in an image-forming apparatus. For low end electrophotographic machines, thermoplastic intermediate transfer members are used due to their low cost; however, the modulus of thermoplastic materials is relatively low from about 1,000 to 2,000 MPa. Materials such as polycarbonate, polyester and polyamide are used for such machines.
For high end electrophotographic machines, thermoplastic or thermoset polyimides or polyamideimides are widely used due to their high modulus (over 3,500 MPa); however, intermediate transfer members using these materials are more expensive to make. Both the raw material cost and manufacturing process cost are higher using thermoplastic or thermoset polyimides or polyamideimides. One issue is that the materials used in higher cost machines do not easily release from metal substrates. An intermediate transfer belt possessing high modulus and excellent release for high end machines is desired.